Brief communication
Postprandial ghrelin suppression is exaggerated following major surgery; implications for nutritional recovery
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* Corresponding author: Gary S Frost G.Frost@surrey.ac.uk
1 Nutrition and Dietetic Research Group, Hammersmith Hospital, Imperial College London, W12 0HS UK
2 Faculty of Medicine, Mashad University of Medical Sciences, Mashad, Iran
3 Cardiothoracic Surgery, NHLI, Hammersmith Hospital, Imperial College London, W12 0HS, UK
4 Department of Metabolic Medicine, Imperial College Faculty of Medicine, London Hammersmith Hospital, London W12 ONN, UK
5 Division of Surgery, Anaesthetics and Intensive Care, Hammersmith Hospital, Imperial College London, W12 0HS, UK
6 School of Biomedical and Molecular Sciences, University of Surrey, Guildford, Surrey, GU2 7XH, UK
Nutrition & Metabolism 2007, 4:20 doi:10.1186/1743-7075-4-20
Published: 8 October 2007Abstract
Meeting patients' nutritional requirements and preventing malnutrition is a challenge following major surgical procedures. The role of ghrelin in nutritional recovery after non-gastrointestinal major surgery is unknown. We used coronary artery bypass grafting (CABG) as an example of anticipated good recovery post major surgery.
Seventeen patients undergoing CABG (mean ± SEM: 70.1 ± 2.2 yrs, BMI 29.1 ± 1.4 kg/m2, 15 male) underwent fasting and postprandial (45 mins after standard test breakfast) blood sampling pre-operatively (day 0), post-operatively (day 6) and at follow-up (day 40). Changes in food intake, biochemical and anthropometric markers of nutritional status were recorded. A comparison was made to 17 matched healthy controls (70.6 ± 2.3 yrs, BMI 28.4 ± 1.3 kg/m2).
We observed significantly increased post-operative and follow-up fasting ghrelin concentrations compared with pre-operatively (pre-op. 402 ± 42 pmol/L vs post-op. 642 ± 97 pmol/L vs follow-up 603 ± 94 pmol/L) (ANOVA p < 0.05). Significantly exaggerated postprandial suppression of ghrelin was seen postoperatively and continued until follow-up (Δ pre-op. 10 ± 51 pmol/L vs Δ post-op. -152 ± 43 pmol/L vs Δ follow-up -159 ± 65 pmol/L, p < 0.05). This was associated with a 50% reduction in food intake {post-op. 4.5 ± 0.5 MJ/D (1076 ± 120 kcal/D) compared with estimated requirements 9.9 ± 0.5 MJ/D (2366 ± 120 kcal/D)}, leading to a 4% weight loss and a 5% reduction in muscle arm circumference loss over length of follow up.
Our data support the hypothesis that prolonged changes in fasting and postprandial plasma ghrelin concentrations are associated with impaired nutritional recovery after CABG. These findings reinforce the need to investigate ghrelin in other patients groups undergoing major surgery.